Albertaceratops nesmoi is a centrosaurine ceratopsid from the lower Oldman Formation (Upper Cretaceous) and is based on a single, almost complete skull collected from the Pinhorn Grazing Reserve of southern Alberta. It has a low, thick, elongate nasal ornamentation, long Triceratops-like brow horns, and a pair of wide-based, large, thickened curled processes originating from the caudolateral margin of the frill. The unfused, adult-sized nasal horncores of Albertaceratops (broken in the holotype) closely resemble the small, juvenile, unfused, nasal horncores of Pachyrhinosaurus but they are tenfold larger.

Referred material comes from equivalent beds in the Judith River Formation of northcentral Montana. A limited phylogenetic analysis of the Ceratopsidae places the new taxon as the basal member of the Centrosaurinae and indicates that robust, elongate postorbital horncores that form a synapomorphy of (Ceratopsidae + Zuniceratops) are also present in Centrosaurinae.

Albertaceratops nesmoi is named to honour both the province where the new dinosaur was found and Cecil Nesmo, a local rancher living near Manyberries, Alberta, who has long supported the study of palaeontology and other research in the area.

The skull of the new horned dinosaur, Albertaceratops nesmoi, in the collections of the Royal Tyrrell Museum, Alberta, Canada. Reconstruction by Donna Sloan/RTMP. Courtesy of Michael. J Ryan and the RTMP.

Collection of the skull of the new horned dinosaur, Albertaceratops nesmoi, from the Pinhorn Grazing Reserve of southern Alberta, Canada. Pictured from left to right are Don Brinkman, Heather Jamniczky, and Brian Matthews. Courtesy of Michael. J Ryan.